I need to add a perspective grid in orthographic view for grease pencil layer
Steps to make a dynamic non-destructive 2d grid in blender:-


  
  Add a Plane
  Add a SubSurf modifier
  Change the subdivision algorithm to simple
  Add a Wireframe modifier
  Tweak the subdivision levels and the wireframe thickness to adjust grid size and density
  


Here's the blend file:-



  I have added a Shadeless material to the grid for easier viewing which may suit your purpose.